A) Field of the Invention
The present invention relates to a confocal microscope, and more particularly to a confocal microscope which generates a defined longitudinal chromatic aberration in the optical beam path.
B) Description of Related Art
Optical systems containing lenses have image aberrations which can be corrected to varying degrees depending on the state of correction. However, there are also applications in which an optical system must have a predetermined longitudinal chromatic aberration at least in some areas without generating other image aberrations, especially transverse chromatic aberrations in the field of view, e.g., in devices provided for imaging object structures located at different depths in different colors in a fixed image plane.
For this purpose, WO 92/01965 discloses an objective with a high chromatic aberration in an arrangement for simultaneous confocal image generation. This is also the subject of DE - A1 4419940. Special objectives which must be free of image aberrations in other respects would have to be developed for these arrangements. "Handbook of Confocal Microscopy", Plenum Press, New York, London 1995, 263,264 discloses objectives which are likewise specially constructed. However, these objectives cannot be optimum with respect to numerical aperture.
The disadvantage of such specially constructed objectives is that they can only be used for this one purpose. Special objectives would have to be developed for different "surface profile types".